package arsmodeller.views;

import java.util.ArrayList;

import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.IMenuListener;
import org.eclipse.jface.action.IMenuManager;
import org.eclipse.jface.action.IToolBarManager;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.action.Separator;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.util.LocalSelectionTransfer;
import org.eclipse.jface.viewers.DoubleClickEvent;
import org.eclipse.jface.viewers.IDoubleClickListener;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerSorter;
import org.eclipse.swt.SWT;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.ui.IActionBars;
import org.eclipse.ui.ISharedImages;
import org.eclipse.ui.IWorkbenchActionConstants;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.part.DrillDownAdapter;
import org.eclipse.ui.part.ViewPart;

/**
 * This sample class demonstrates how to plug-in a new workbench view. The view
 * shows data obtained from the model. The sample creates a dummy model on the
 * fly, but a real implementation would connect to the model available either in
 * this or another plug-in (e.g. the workspace). The view is connected to the
 * model using a content provider.
 * <p>
 * The view uses a label provider to define how model objects should be
 * presented in the view. Each view can present the same model objects using
 * different labels and icons, if needed. Alternatively, a single label provider
 * can be shared between views in order to ensure that objects of the same type
 * are presented in the same way everywhere.
 * <p>
 */

public class ObjectView extends ViewPart {

	/**
	 * The ID of the view as specified by the extension.
	 */
	public static final String ID = "arsmodeller.views.ObjectView";

	private TreeViewer viewer;
	private DrillDownAdapter drillDownAdapter;
	private Action action1;
	private Action action2;
	private Action doubleClickAction;
	private ViewContentProvider vcp;

	/*
	 * The content provider class is responsible for providing objects to the
	 * view. It can wrap existing objects in adapters or simply return objects
	 * as-is. These objects may be sensitive to the current input of the view,
	 * or ignore it and always show the same content (like Task List, for
	 * example).
	 */

	class TreeObject implements IAdaptable {
		private String name;
		private TreeParent parent;

		public TreeObject(String name) {
			this.name = name;
		}

		public String getName() {
			return name;
		}

		public void setParent(TreeParent parent) {
			this.parent = parent;
		}

		public TreeParent getParent() {
			return parent;
		}

		public String toString() {
			return getName();
		}

		public Object getAdapter(Class key) {
			return null;
		}
	}

	class TreeParent extends TreeObject {
		private ArrayList children;

		public TreeParent(String name) {
			super(name);
			children = new ArrayList();
		}

		public void addChild(TreeObject child) {
			children.add(child);
			child.setParent(this);
		}

		public void removeChild(TreeObject child) {
			children.remove(child);
			child.setParent(null);
		}

		public TreeObject[] getChildren() {
			return (TreeObject[]) children.toArray(new TreeObject[children
					.size()]);
		}

		public boolean hasChildren() {
			return children.size() > 0;
		}
	}

	class ViewContentProvider implements IStructuredContentProvider,
			ITreeContentProvider {
		private TreeParent invisibleRoot;

		public void inputChanged(Viewer v, Object oldInput, Object newInput) {
		}

		public void dispose() {
		}

		public Object[] getElements(Object parent) {
			if (parent.equals(getViewSite())) {
				if (invisibleRoot == null)
					initialize();
				return getChildren(invisibleRoot);
			}
			return getChildren(parent);
		}

		public Object getParent(Object child) {
			if (child instanceof TreeObject) {
				return ((TreeObject) child).getParent();
			}
			return null;
		}

		public Object[] getChildren(Object parent) {
			if (parent instanceof TreeParent) {
				return ((TreeParent) parent).getChildren();
			}
			return new Object[0];
		}

		public boolean hasChildren(Object parent) {
			if (parent instanceof TreeParent)
				return ((TreeParent) parent).hasChildren();
			return false;
		}

		/*
		 * We will set up a dummy model to initialize tree heararchy. In a real
		 * code, you will connect to a real model and expose its hierarchy.
		 */
		private void initialize() {
			TreeParent prcs = new TreeParent("Processes");
			TreeObject SampleProcess = new TreeObject("Sample Process");
			TreeObject DataFlow = new TreeObject("DataFlow");
			TreeObject SequesceFlow = new TreeObject("Sequence Flow");
			TreeParent CF = new TreeParent("Control Flow");
			prcs.addChild(SampleProcess);
			CF.addChild(SequesceFlow);
			CF.addChild(DataFlow);

			TreeObject to4 = new TreeObject("Leaf 4");
			TreeParent p2 = new TreeParent("Parent 2");
			p2.addChild(to4);

			TreeParent root = new TreeParent("Objects");
			root.addChild(prcs);
			root.addChild(CF);

			invisibleRoot = new TreeParent("");
			invisibleRoot.addChild(root);
		}
	}

	class ViewLabelProvider extends LabelProvider {

		public String getText(Object obj) {
			return obj.toString();
		}

		public Image getImage(Object obj) {
			String imageKey = ISharedImages.IMG_OBJ_ELEMENT;
			if (obj instanceof TreeParent)
				imageKey = ISharedImages.IMG_OBJ_FOLDER;
			return PlatformUI.getWorkbench().getSharedImages()
					.getImage(imageKey);
		}
	}

	class NameSorter extends ViewerSorter {
	}

	/**
	 * The constructor.
	 */
	public ObjectView() {
	}

	/**
	 * This is a callback that will allow us to create the viewer and initialize
	 * it.
	 */
	public void createPartControl(Composite parent) {
		viewer = new TreeViewer(parent, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);
		drillDownAdapter = new DrillDownAdapter(viewer);
		int operations = DND.DragStart | DND.DragSetData | DND.DragOver;

		// viewer.addDragSupport(operations, transferTypes, listener)
		ViewContentProvider vcp = new ViewContentProvider();
		viewer.setContentProvider(vcp);
		viewer.setLabelProvider(new ViewLabelProvider());
		viewer.setSorter(new NameSorter());
		viewer.setInput(getViewSite());
		Transfer[] transferTypes = new Transfer[] { LocalSelectionTransfer
				.getTransfer() };
		// Create the help context id for the viewer's control
		PlatformUI.getWorkbench().getHelpSystem()
				.setHelp(viewer.getControl(), "ARSModeller.viewer");
		makeActions();
		hookContextMenu();
		hookDoubleClickAction();
		contributeToActionBars();
	}

	public TreeViewer getTreeViewer() {
		return viewer;
	}

	private void hookContextMenu() {
		MenuManager menuMgr = new MenuManager("#PopupMenu");
		menuMgr.setRemoveAllWhenShown(true);
		menuMgr.addMenuListener(new IMenuListener() {
			public void menuAboutToShow(IMenuManager manager) {
				ObjectView.this.fillContextMenu(manager);
			}
		});
		Menu menu = menuMgr.createContextMenu(viewer.getControl());
		viewer.getControl().setMenu(menu);
		getSite().registerContextMenu(menuMgr, viewer);
	}

	private void contributeToActionBars() {
		IActionBars bars = getViewSite().getActionBars();
		fillLocalPullDown(bars.getMenuManager());
		fillLocalToolBar(bars.getToolBarManager());
	}

	private void fillLocalPullDown(IMenuManager manager) {
		manager.add(action1);
		manager.add(new Separator());
		manager.add(action2);
	}

	private void fillContextMenu(IMenuManager manager) {
		manager.add(action1);
		manager.add(action2);
		manager.add(new Separator());
		drillDownAdapter.addNavigationActions(manager);
		// Other plug-ins can contribute there actions here
		manager.add(new Separator(IWorkbenchActionConstants.MB_ADDITIONS));
	}

	private void fillLocalToolBar(IToolBarManager manager) {
		manager.add(action1);
		manager.add(action2);
		manager.add(new Separator());
		drillDownAdapter.addNavigationActions(manager);
	}

	private void makeActions() {
		action1 = new Action() {
			public void run() {
				showMessage("Action 1 executed");
			}
		};
		action1.setText("Action 1");
		action1.setToolTipText("Action 1 tooltip");
		action1.setImageDescriptor(PlatformUI.getWorkbench().getSharedImages()
				.getImageDescriptor(ISharedImages.IMG_OBJS_INFO_TSK));

		action2 = new Action() {
			public void run() {
				showMessage("Action 2 executed");
			}
		};
		action2.setText("Action 2");
		action2.setToolTipText("Action 2 tooltip");
		action2.setImageDescriptor(PlatformUI.getWorkbench().getSharedImages()
				.getImageDescriptor(ISharedImages.IMG_OBJS_INFO_TSK));
		doubleClickAction = new Action() {
			public void run() {
				ISelection selection = viewer.getSelection();
				Object obj = ((IStructuredSelection) selection)
						.getFirstElement();
				showMessage("Double-click detected on " + obj.toString());
			}
		};
	}

	private void hookDoubleClickAction() {
		viewer.addDoubleClickListener(new IDoubleClickListener() {
			public void doubleClick(DoubleClickEvent event) {
				doubleClickAction.run();
			}
		});
	}

	private void showMessage(String message) {
		MessageDialog.openInformation(viewer.getControl().getShell(),
				"Objects", message);
	}

	/**
	 * Passing the focus request to the viewer's control.
	 */
	public void setFocus() {
		viewer.getControl().setFocus();
	}
}